An EC_KEY represents a public key and (optionally) an associated private key. A new EC_KEY (with no associated curve) can be constructed by calling EC_KEY_new().
The reference count for the newly created EC_KEY is initially set to 1. A curve can be associated with the EC_KEY by calling
EC_KEY_set_group().

Alternatively a new EC_KEY can be constructed by calling EC_KEY_new_by_curve_name() and supplying the nid of the associated curve. Refer to EC_GROUP_new(3) for a description of curve names. This function simply wraps calls to EC_KEY_new() and
EC_GROUP_new_by_curve_name().

Calling EC_KEY_free() decrements the reference count for the EC_KEY object, and if it has dropped to zero then frees the memory associated
with it.
If key is NULL nothing is done.

EC_KEY_copy() copies the contents of the EC_KEY in src into dest.

EC_KEY_dup() creates a new EC_KEY object and copies ec_key into it.

EC_KEY_up_ref() increments the reference count associated with the EC_KEY object.

EC_KEY_generate_key() generates a new public and private key for the supplied eckey object. eckey must have an EC_GROUP object
associated with it before calling this function. The private key is a random integer (0 < priv_key < order, where order is the order
of the EC_GROUP object). The public key is an EC_POINT on the curve calculated by multiplying the generator for the curve by the
private key.

EC_KEY_check_key() performs various sanity checks on the EC_KEY object to confirm that it is valid.

EC_KEY_set_public_key_affine_coordinates() sets the public key for key based on its affine co-ordinates, i.e. it constructs an EC_POINT
object based on the supplied x and y values and sets the public key to be this EC_POINT. It will also performs certain sanity checks
on the key to confirm that it is valid.

The functions EC_KEY_get0_group(), EC_KEY_set_group(), EC_KEY_get0_private_key(), EC_KEY_set_private_key(), EC_KEY_get0_public_key(), and EC_KEY_set_public_key() get and set the EC_GROUP object, the private key and the EC_POINT public key for the key respectively.

The functions EC_KEY_get_conv_form() and EC_KEY_set_conv_form() get and set the point_conversion_form for the key. For a description
of point_conversion_forms please refer to EC_POINT_new(3).

EC_KEY_set_flags() sets the flags in the flags parameter on the EC_KEY object. Any flags that are already set are left set. The currently defined standard flags are EC_FLAG_NON_FIPS_ALLOW and EC_FLAG_FIPS_CHECKED. In addition there is the flag EC_FLAG_COFACTOR_ECDH which is specific to ECDH and is defined in ecdh.h. EC_KEY_get_flags returns the current flags that are set for this EC_KEY. EC_KEY_clear_flags clears the flags indicated by the flags parameter. All other flags are left in their existing state.

EC_KEY_set_asn1_flag() sets the asn1_flag on the underlying EC_GROUP object (if set). Refer to EC_GROUP_copy(3) for further information on the asn1_flag.

EC_KEY_precompute_mult() stores multiples of the underlying EC_GROUP generator for faster point multiplication. See also EC_POINT_add(3).